Thread repair tool

ABSTRACT

A thread repair tool for repairing damaged threads on a screw is disclosed. The thread repair tool includes a tool body and plural rollers. The tool body has at least one surface provided with a thread repair blade that has a tooth pitch identical to a thread pitch of the threads to be repaired. The rollers are separated from the tool body by a gap. The thread repair tool further includes an adjusting means for adjusting the gap so as to hold the screw between the tool body and the rollers.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to thread repair devices, and more particularly to a tool for repairing damaged male threads.

2. Description of Related Art

Thread repair tools are designed for repairing screw threads with thread cutting molds having corresponding screw diameters. One conventional thread repair tool, as disclosed in Japan Patent Publication No. 2006-326731A, is composed of two die halves that only fit threads of a certain thread pitch, screw diameter and screw type. For repairing threads with different designs, the conventional tool would need plenty of said dies, being inconvenient to both carry and use.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a thread repair tool that is capable of dealing with screws of various diameters, without using different dies.

According to the present invention, a thread repair tool used for repairing a set of damaged threads on a screw comprises a tool body having at least one surface provided with a thread repair blade that has a tooth pitch identical to a thread pitch of the set of threads, plural rollers separated from the tool body by a gap, and an adjusting means for such adjusting the gap that the screw is firmly held between the tool body and the rollers.

Thereby, the disclosed thread repair tool has the distance between the thread repair blade and the rollers adjusted to fit the to-be-repaired screw's diameter, thereby facilitating threads repair operation. This allows the disclosed thread repair tool to adapt itself to screws with different diameters, opposite to the prior-art device that needs many dies. It is thus evident that the present invention overcomes the shortcomings of the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention as well as a preferred mode of use, further objectives and advantages thereof will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of one preferred embodiment of the present invention;

FIG. 2 is an exploded view of the preferred embodiment of the present invention;

FIG. 3 is another perspective view of the preferred embodiment of the present invention, wherein the adjusting means and the rollers are separated by an enlarged gap;

FIG. 4 is an applied view of the preferred embodiment of the present invention;

FIG. 5 is a cross-sectional view of FIG. 4; and

FIG. 6 is a perspective view of another preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While a preferred embodiment provided hereinafter for illustrating the concept of the present invention as described above, it is to be understood that the components of the embodiment shown in the accompanying drawings are depicted for the sake of easy explanation and need not to be made to exact scale.

Please refer to FIG. 1 through FIG. 3 for one embodiment of the present invention. In the present embodiment, the thread repair tool is composed of a tool body 10, a plurality of rollers 20 and an adjusting means.

The tool body 10 has at least one surface provided with a thread repair blade 11 constructed from a row of teeth. The thread repair blade 11 has a tooth pitch matching the thread pitch of a set of threads to be repaired. In the present embodiment, the tool body 10 is a rectangular plank with its four lateral surfaces each provided with a thread repair blade 11, 12, 13 or 14. Preferably, the thread repair blades 11, 12, 13 and 14 on the different surfaces have different tooth pitches. Thereby, a single said tool body 10 is useful to repair screws of different thread pitches. In practice, more than one said tool bodies having different thread repair blades may be provided to adapt the thread repair tool to screws of more different specifications.

The rollers 20 are separated from the tool body 10 by a gap. Preferably, as shown in FIG. 5, the rollers 20 coming in pair are arranged abreast. The paired rollers 20 jointly define a supporting area facing the tool body 10 for a to-be-repaired screw to lean thereon, and the thread repair blade 11 is aligned with the supporting area between the rollers 20.

The adjusting means includes a base 30, an adjusting screw 40 and a sliding block 50. The base 30 has a lengthwise sliding guide 31, and the rollers 20 are mounted on the base 30 to roll with respect to the base 30. The tool body 10 is deposited on the sliding block 50. Preferably, the tool body 10 is detachably fixed to the sliding block 50. For example, the sliding block 50 is formed with an assembling hole 52, and the tool body 10 is centrally provided with a through hole 17, so that a fixing screw 15 passing through a gasket 16 and the through hole 17 of the tool body 10 can engage with threads formed in the assembling hole 52 of the sliding block 50 to fix the tool body 10 on the sliding block 50. The sliding block 50 is slidably mounted on the sliding guide 31 so it can linearly slide in a sliding direction. The sliding block 50 has a threaded hole 51. The adjusting screw 40 is such assembled to the base 30 in the sliding direction that it is rotatably independent of the base 30 and then engages with the threaded hole 51. By stating that the adjusting screw 40 “is rotatably independent of the base 30”, it means that when rotating, the adjusting screw 40 does not slide axially with respect to the base 30. Thereby, the rotation of the adjusting screw 40 makes the sliding block 50 slide along the sliding guide 31, thereby varying the gap.

Referring to FIGS. 4 and 5, in use, a to-be-repaired screw 1 is placed between the tool body 10 and the rollers 20, wherein the thread repair blade 11 facing the screw 1 has its tooth pitch matching the thread pitch of the threads 2 of the screw 1. Afterward, the adjusting means is operated to adjust the gap between the thread repair blade 11 and the roller 20 until the screw 1 is firmly held between the supporting area of the rollers 20 and the thread repair blade 11. Then the screw 1 rotates with respect to the thread repair tool. For example, the screw 1 is held still and the thread repair tool rotates against the screw 1, thereby correcting the threads 2 of the screw 1 in both shape and pitch.

In an alternative operation of the present invention, for achieving relative rotation between the screw 1 and the thread repair tool, it may be the case where the thread repair tool is held still, and the screw 1 revolves while being held by the thread repair blade 11 and the rollers 20, so as to similarly repair the threads 2.

Referring to FIG. 6, according to another embodiment of the present invention, the adjusting means includes a base 60, an adjusting screw 70 and a sliding block 80. The base 60 has a lengthwise sliding guide 61 and a threaded hole 62. The rollers 20 are rotatably mounted on the sliding block 80, and the sliding block 80 is such mounted on the sliding guide 61 that it can slide in a sliding direction. The position of the tool body 10 related to the base 60 is fixed. The adjusting screw 70 engages with and passes through the threaded hole 62 so that its free end 71 is connected to the sliding block 80. Thereby, when the adjusting screw 70 rotates, the sliding block 80 and the rollers 20 thereon slide accordingly on the sliding guide 61.

A main advantage of the present invention is that the thread repair tool can fit screws with different diameters by adjusting the gap between the tool body and the rollers, without needing many dies as the prior-art device does, making the tool convenient to use.

Another advantage of the present invention is that the single tool body can have multiple thread repair blades so as to match screws with both forward and backward threads, screws with different thread pitches, and/or screws of different types, making the tool more applicable.

Still another advantage of the present invention is that it allows the threads under repair to be visible to the relevant operator so that the operator can perfectly repair the threads by applying different levels of pressing force to the thread repair blade.

The present invention has been described with reference to the preferred embodiments and it is understood that the embodiments are not intended to limit the scope of the present invention. Moreover, as the contents disclosed herein should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present invention should be encompassed by the appended claims. 

What is claimed is:
 1. A thread repair tool, for repairing a set of threads on a screw, the thread repair tool comprising: a tool body having at least one surface provided with a thread repair blade that includes a row of teeth and has a tooth pitch identical to a thread pitch of the set of threads; a plurality of rollers being separated from the tool body by a gap; and an adjusting means for adjusting the gap so as to hold the screw between the tool body and the rollers.
 2. The thread repair tool of claim 1, wherein the adjusting means comprises a base, an adjusting screw and a sliding block, the base having a lengthwise sliding guide, the rollers being rotatably mounted on the base, the tool body being fixed to the sliding block, the sliding block being slidably mounted on the sliding guide so the sliding block is allowed to linearly slide in a sliding direction, the sliding block having a threaded hole, and the adjusting screw being rotatably independent of the base and then engaging with the threaded hole, whereby rotation of the adjusting screw makes the sliding block slide along the sliding guide.
 3. The thread repair tool of claim 1, wherein the adjusting means comprises a base, an adjusting screw and a sliding block, the base having a lengthwise sliding guide and a threaded hole, the rollers being rotatably mounted on the sliding block, the sliding block being slidably mounted on the sliding guide so the sliding block is allowed to linearly slide in a sliding direction, a position of the tool body related to the base being fixed, and the adjusting screw engaging with and passing through the threaded hole so that a free end thereof is connected to the sliding block, whereby rotation of the adjusting screw makes the sliding block slide along the sliding guide.
 4. The thread repair tool of claim 1, wherein the tool body is a polygonal plank having each lateral surface thereof provided with one said thread repair blade and the thread repair blades on the different lateral surfaces of the polygonal plank have different thread pitches.
 5. The thread repair tool of claim 1, wherein the rollers coming in pair are arranged abreast to jointly define a supporting area facing the tool body for the screw to lean thereon. 